Height comparators have been provided heretofore in a variety of designs useful in comparing the height of a specimen with the height of an equivalent number of precision machinist blocks such as Johannson blocks. Such equipment customarily makes use of a transfer stand adjustably supporting a carriage to which is secured a suitable height sensor, such as a dial indicator, and electronic indicator or the like means. Examples of such prior comparators are found in U.S. Pat. Nos. to Cady 1,459,500; Lester 1,949,280; Conover 2,081,738; Temple 2,083,759; Aller et al 2,370,220; Graham 2,717,449; Huyser 3,040,445 and Perlotto 4,251,922.
These and the like prior teachings are subject to numerous deficiencies and shortcomings avoided by this invention. Although some of these prior proposals embrace provision for making both a coarse and a fine adjustment of the indicator carried by the transfer stand, they lack any provision for further and more highly precise adjustment for the indicator probe. Additionally prior constructions are complex and involve a number of moving parts inherently incorporating loss motion or backlash. Another shortcoming is the lack of a micro-adjuster interconnecting the height sensor and the transfer stand carriage. More particularly, the prior art surface gauges utilizing transfer stand equipment are incapable of adjustment to accuracies of a few millionths of an inch.